The Korean Peninsula migraine -- outcomes no one wants

Even a best-case scenario would mean decades of hardship

The great problem in knowing whether North Korea is about to explode is in judging which words to take seriously and which to ignore. For years, leaders of the world's only Communist family dynasty have threatened to drown South Korea, the United States and Japan in a lake of fire. Past U.S. presidents have shrugged off these threats and worked behind the scenes with China and South Korea to find safe ways to tighten the pressure on the regime.

But things have changed, and it's now time for the world to pay closer attention. There are two important changes. First, U.S. President Donald Trump is less willing than his predecessors to handle things quietly. Instead, Trump has approached North Korea with warships and threatened to "solve" North Korea with or without Chinese help. He has also said he'd be willing to meet with Kim Jong Un. Depending on what might happen in that hypothetical meeting, either a negotiated settlement or war might become more likely.

The second difference is much more important. In fairness to Trump, a more assertive response is warranted: Satellite imagery tells us that the North in recent years has made substantial progress on an intercontinental ballistic missile capable of reaching the U.S. mainland and on miniaturizing a nuclear warhead so a missile can carry it. This is why former President Barack Obama warned Trump that North Korea was likely to be his biggest foreign policy challenge.

It's one thing to negotiate with an erratic absolute dictator; it's quite another when that dictator can test your defense by sending a nuclear-armed missile toward some of your largest cities. Would mutually assured destruction deter Kim Jong Un? We can't know for sure until the moment of no return.

Trump's options are no better than Obama's. Sanctions won't change minds in Pyongyang -- the leadership pays no political price for hardships imposed on it people. Sanctions also help Kim's government persuade North Koreans that outsiders want to destroy them.

Also, China is unlikely to offer much help -- it fears a Korean crisis would send sick and starving refugees streaming across its border.

That said, there are plenty of cool heads around President Trump who will make clear that he can't afford to launch an ultra-high-risk surprise strike unless and until it's clear that every potential alternative has been exhausted. The president's dramatic warnings are still directed mainly at China in hopes that President Xi Jinping will help dramatically increase the pressure on Pyongyang.

Trump also wants to reassure allies in South Korea and Japan that he understands the severity of the growing threat -- though his recent comments about the need for South Korea to pay more for its defense and to renegotiate its trade agreement with the U.S. won't help. Trump may also be hoping that his tough talk will create doubts, perhaps dissension, within the North Korean leadership.

For now, the North's missile technology has not reached the danger zone, and Trump isn't about to start a war.

Yet, short of open conflict, there is another important risk to consider. Imagine a best-case scenario: A coup inside North Korea leads to peaceful regime change. China steps in to ensure control of nuclear weapons and material, and agrees to a plan to reunify North and South. Should the North collapse, it would leave more than 25 million people without a country.

Who would pay to bring the Koreas back together?

The evidence suggests Korea's reunification would be far more expensive than Germany's. When the Berlin Wall fell in 1989, East Germany's population was one quarter that of West Germany's. The country's per capita income was about one third that of West Germany. Though separated by the Iron Curtain, trade ties were well-developed. By contrast, North Korea's population is more than half that of South Korea, but its per capita income is less than 5 percent. The two countries have almost no commercial relationship.

To create anything close to parity of prosperity, a reunified Korea will need tens of billions of dollars per year invested over several decades in infrastructure, education and agriculture. And how difficult will it be for millions of profoundly disoriented North Koreans, plucked from the lifeboats of their isolated country, to find work in one of the world's most technologically advanced economies and societies? What happens to those people if they can't find work?

The world will need answers to these questions before the moment when Kim Jong Un can launch a nuclear attack on the U.S. mainland. That day is now much closer than anyone outside North Korea would wish.

Ian Bremmer is the president of Eurasia Group and author of "Superpower: Three Choices for America's Role in the World." He is on Twitter as @ianbremmer and Facebook as Ian Bremmer.